In an existing Wireless Fidelity (WiFi) system, a premise of data communication between a STA and an AP is that the STA is already associated with the AP. Before the association, identity of the STA needs to be verified by the AP first, and the identity verification process may also be referred to as an authentication process. After the authentication is complete, the STA initiates the association process between the STA and the AP, and if the association succeeds, the STA may perform data communication with the AP.
However, in the existing WiFi system, all authentication processes or association processes between multiple STAs and an AP are relatively independent, that is, each of the different STAs contends for a channel and sends an authentication frame or an association request frame of the STA. After receiving the authentication frames or the association request frames, the AP sends a separate corresponding response to each STA, and these responses occupy relatively more downlink resources.